350, I agree.
Presently, I'm in the middle of studying the Gleim ATP written prep book too. Some of the questions on alternates and fuel reserves for Supp. Flag, Domestic and Commercial are all blurring together. Its a big book with lots of questions, epecially the performance stuff. Memorizing answers isn't a policy I'd follow. You're better off taking your time to understand the questions and answers more thoroughly. Eventually, you will need to have a working knoweldge of this stuff so it doesn't hurt to try understanding the logicbehind an answer. As far as the calculations go, make sure you have an electronic flight computer for the IFR flights.